misc: consistency of comments and dispatcher instance creation

examples/echo_bot.py

@@ -3,7 +3,7 @@ import logging
 import sys
 from os import getenv
 
-from aiogram import Bot, Dispatcher, html
+from aiogram import Bot, Dispatcher, Router, html
 from aiogram.client.default import DefaultBotProperties
 from aiogram.enums import ParseMode
 from aiogram.filters import CommandStart
@@ -13,10 +13,11 @@ from aiogram.types import Message
 TOKEN = getenv("BOT_TOKEN")
 
 # All handlers should be attached to the Router (or Dispatcher)
-dp = Dispatcher()
+
+echo_router = Router()
 
 
-@dp.message(CommandStart())
+@echo_router.message(CommandStart())
 async def command_start_handler(message: Message) -> None:
     """
     This handler receives messages with `/start` command
@@ -29,7 +30,7 @@ async def command_start_handler(message: Message) -> None:
     await message.answer(f"Hello, {html.bold(message.from_user.full_name)}!")
 
 
-@dp.message()
+@echo_router.message()
 async def echo_handler(message: Message) -> None:
     """
     Handler will forward receive a message back to the sender
@@ -47,6 +48,11 @@ async def echo_handler(message: Message) -> None:
 async def main() -> None:
     # Initialize Bot instance with default bot properties which will be passed to all API calls
     bot = Bot(token=TOKEN, default=DefaultBotProperties(parse_mode=ParseMode.HTML))
+
+    dp = Dispatcher()
+
+    dp.include_router(echo_router)
+
     # And the run events dispatching
     await dp.start_polling(bot)